In these grinders, when the material to be ground is not uniformly distributed over the entire width of the grinding track, particularly when large pieces are introduced onto the track, the roller tends to position itself slantwise in relation to the ring, which reduces its efficiency. To overcome this drawback, the two arms could be attached rigidly to one another, but this would lead, in the event of a large piece or of a nongrindable object passing between the ring and the roller, to the grinding force exerted by the roller being concentrated on a reduced area of the ring, with the occurrence of excessive mechanical stresses in the roller and the ring.
The object of the present invention is to provide simple means for limiting the slantwise positioning of the roller in relation to the ring while, at the same time, limiting the grinding pressures and, consequently, the mechanical stresses, to within acceptable values, as well as for contributing to a reduction in the oscillatory movements of the roller and its supports.